Wastewater from many commercial and industrial facilities, such as restaurants, usually contains large amounts of greasy wastes including fats, oils, waxes, and other high molecular-mass fatty acids. In wastewater treatment plants, these greasy wastes interfere with the proper operation of the treatment process. For example, grease has a tendency to coat the insides of the pipes and tank walls that are used to transport and store the sludge and scum from wastewater. Also, excessive quantities of grease may tend to plug the trickling filters or coat the biological floc that are used in the activated sludge processes of wastewater treatment plants. Consequently, in many states, restaurants and others who produce greasy wastewater are required by law to use on site grease traps to collect from the wastewater a major portion of the large amounts of greasy wastes that they produce.
Heretofore, the greasy waste collected within these grease traps has been disposed of in several different ways. It has been, for example, collected and transported to a municipal wastewater treatment plant and treated along with the influent wastewater, collected in large drums and recycled, collected and placed inside of containers to be disposed of in a landfill, or collected and dumped directly into a landfill Direct dumping of the greasy wastewater can, if it is liquid or in semi-liquid form, contaminate the water supply of a municipality. Because of the difficulty in the collection and disposition of greasy waste, more and more municipal wastewater treatment plants are refusing to accept greasy wastewater In addition, in some locales the size and quantity of the containers used to dispose of grease into landfills has been restricted by law, and the disposal of greasy wastewater directly into a landfill is prohibited by both federal and state laws.
However, some state regulations permit liquid wastes to be admixed with a bladeable material and deposited in a landfill. For example, a regulation of the Georgia Department of Natural Resources, Environmental Protection Division, provides that liquid waste, if admixed with a bladeable material to render it nonliquid, is acceptable for disposal at a landfill "Bladeable" is defined in the regulations as capable of being shovelled, scooped, or pushed by a "blade." It is, therefore, to a method and apparatus for extracting greasy waste from wastewater and admixing the wastes thus extracted with a bladeable material that the present invention is directed.